@mcintyre94/accounts

@solana/accounts

This package contains types and helper methods for representing, fetching and decoding Solana accounts. It can be used standalone, but it is also exported as part of the Solana JavaScript SDK @solana/web3.js@experimental.

It provides a unified definition of a Solana account regardless of how it was retrieved and can represent both encoded and decoded accounts. It also introduces the concept of a MaybeAccount which represents a fetched account that may or may not exist on-chain whilst keeping track of its address in both cases.

Helper functions are provided for fetching, parsing and decoding accounts as well as asserting that an account exists.

// Fetch.
const myAddress = address('1234..5678');
const myAccount = fetchAccount(rpc, myAddress);
myAccount satisfies MaybeEncodedAccount<'1234..5678'>;

// Assert.
assertAccountExists(myAccount);
myAccount satisfies EncodedAccount<'1234..5678'>;

// Decode.
type MyAccountData = { name: string; age: number };
const myDecoder: Decoder<MyAccountData> = getStructDecoder([
    ['name', getStringDecoder({ size: getU32Decoder() })],
    ['age', getU32Decoder()],
]);
const myDecodedAccount = decodeAccount(myAccount, myDecoder);
myDecodedAccount satisfies Account<MyAccountData, '1234..5678'>;

Types

BaseAccount

The BaseAccount type defines the attributes common to all Solana accounts. Namely, it contains everything stored on-chain except the account data itself.

const BaseAccount: BaseAccount = {
    executable: false,
    lamports: lamports(1_000_000_000n),
    programAddress: address('1111..1111'),
};

This package also exports a BASE_ACCOUNT_SIZE constant representing the size of the BaseAccount attributes in bytes.

const myTotalAccountSize = myAccountDataSize + BASE_ACCOUNT_SIZE;

Account and EncodedAccount

The Account type contains all the information relevant to a Solana account. It contains the BaseAccount described above as well as the account data and the address of the account.

The account data can be represented as either a Uint8Array — meaning the account is encoded — or a custom data type — meaning the account is decoded.

// Encoded.
const myEncodedAccount: Account<Uint8Array, '1234..5678'> = {
    address: address('1234..5678'),
    data: new Uint8Array([1, 2, 3]),
    executable: false,
    lamports: lamports(1_000_000_000n),
    programAddress: address('1111..1111'),
};

// Decoded.
type MyAccountData = { name: string; age: number };
const myDecodedAccount: Account<MyAccountData, '1234..5678'> = {
    address: address('1234..5678'),
    data: { name: 'Alice', age: 30 },
    executable: false,
    lamports: lamports(1_000_000_000n),
    programAddress: address('1111..1111'),
};

The EncodedAccount type can also be used to represent an encoded account and is equivalent to an Account with a Uint8Array account data.

myEncodedAccount satisfies EncodedAccount<'1234..5678'>;

MaybeAccount and MaybeEncodedAccount

The MaybeAccount type is a union type representing an account that may or may not exist on-chain. When the account exists, it is represented as an Account type with an additional exists attribute set to true. When it does not exist, it is represented by an object containing only the address of the account and an exists attribute set to false.

// Account exists.
const myExistingAccount: MaybeAccount<MyAccountData, '1234..5678'> = {
    exists: true,
    address: address('1234..5678'),
    data: { name: 'Alice', age: 30 },
    executable: false,
    lamports: lamports(1_000_000_000n),
    programAddress: address('1111..1111'),
};

// Account does not exist.
const myMissingAccount: MaybeAccount<MyAccountData, '8765..4321'> = {
    exists: false,
    address: address('8765..4321'),
};

Similarly to the Account type, the MaybeAccount type can be used to represent an encoded account by using the Uint8Array data type or by using the MaybeEncodedAccount helper type.

// Encoded account exists.
const myExistingAccount: MaybeEncodedAccount<'1234..5678'> = {
    exists: true,
    address: address('1234..5678'),
    data: new Uint8Array([1, 2, 3]),
    // ...
};

// Encoded account does not exist.
const myMissingAccount: MaybeEncodedAccount<'8765..4321'> = {
    exists: false,
    address: address('8765..4321'),
};

Functions

assertAccountExists()

Given a MaybeAccount, this function asserts that the account exists and allows it to be used as an Account type going forward.

const myAccount: MaybeEncodedAccount<'1234..5678'>;
assertAccountExists(myAccount);

// Now we can use myAccount as an Account.
myAccount satisfies EncodedAccount<'1234..5678'>;

assertAccountsExist()

Given an array of MaybeAccounts, this function asserts that all the accounts exist and allows them to be used as an array of Accounts going forward.

const myAccounts: MaybeEncodedAccount<Address>[];
assertAccountsExist(myAccounts);

// Now we can use them as an array of accounts
for (const a of myAccounts) {
  a satisfies EncodedAccount<Address>;
}

parseBase64RpcAccount()

This function parses a base64-encoded account provided by the RPC client into an EncodedAccount type or a MaybeEncodedAccount type if the raw data can be set to null.

const myAddress = address('1234..5678');
const myRpcAccount = await rpc.getAccountInfo(myAddress, { encoding: 'base64' }).send();
const myAccount: MaybeEncodedAccount<'1234..5678'> = parseBase64RpcAccount(myRpcAccount);

parseBase58RpcAccount()

This function parses a base58-encoded account provided by the RPC client into an EncodedAccount type or a MaybeEncodedAccount type if the raw data can be set to null.

const myAddress = address('1234..5678');
const myRpcAccount = await rpc.getAccountInfo(myAddress, { encoding: 'base58' }).send();
const myAccount: MaybeEncodedAccount<'1234..5678'> = parseBase58RpcAccount(myRpcAccount);

parseJsonRpcAccount()

This function parses an arbitrary jsonParsed account provided by the RPC client into an Account type or a MaybeAccount type if the raw data can be set to null. The expected data type should be explicitly provided as the first type parameter.

const myAccount: Account<MyData> = parseJsonRpcAccount<MyData>(myJsonRpcAccount);

fetchEncodedAccount()

This function fetches a MaybeEncodedAccount from the provided RPC client and address. It uses the getAccountInfo RPC method under the hood with base64 encoding and an additional configuration object can be provided to customize the behavior of the RPC call.

const myAddress = address('1234..5678');
const myAccount: MaybeEncodedAccount<'1234..5678'> = await fetchEncodedAccount(rpc, myAddress);

// With custom configuration.
const myAccount: MaybeEncodedAccount<'1234..5678'> = await fetchEncodedAccount(rpc, myAddress, {
    abortSignal: myAbortController.signal,
    commitment: 'confirmed',
});

fetchEncodedAccounts()

This function fetches an array of MaybeEncodedAccount from the provided RPC client and an array of addresses. It uses the getMultipleAccounts RPC method under the hood with base64 encodings and an additional configuration object can be provided to customize the behavior of the RPC call.

const myAddressA = address('1234..5678');
const myAddressB = address('8765..4321');
const [myAccountA, myAccountB] = await fetchEncodedAccounts(rpc, [myAddressA, myAddressB]);
myAccountA satisfies MaybeEncodedAccount<'1234..5678'>;
myAccountB satisfies MaybeEncodedAccount<'8765..4321'>;

// With custom configuration.
const [myAccountA, myAccountB] = await fetchEncodedAccounts(rpc, [myAddressA, myAddressB], {
    abortSignal: myAbortController.signal,
    commitment: 'confirmed',
});

fetchJsonParsedAccount()

This function fetches a MaybeAccount from the provided RPC client and address by using getAccountInfo under the hood with the jsonParsed encoding. It may also return a MaybeEncodedAccount if the RPC client does not know how to parse the account at the requested address. In any case, the expected data type should be explicitly provided as the first type parameter.

type TokenData = { mint: Address; owner: Address };
const myAccount = await fetchJsonParsedAccount<TokenData>(rpc, myAddress);
myAccount satisfies MaybeAccount<TokenData> | MaybeEncodedAccount;

// With custom configuration.
const myAccount = await fetchJsonParsedAccount<TokenData>(rpc, myAddress, {
    abortSignal: myAbortController.signal,
    commitment: 'confirmed',
});

fetchJsonParsedAccounts()

Similarly to the fetchJsonParsedAccount method, this method fetches an array of MaybeAccount from a provided RPC client and an array of addresses. It uses the getMultipleAccounts RPC method under the hood with the jsonParsed encoding. It may also return a MaybeEncodedAccount instead of the expected MaybeAccount if the RPC client does not know how to parse some of the requested accounts. In any case, the array of expected data types should be explicitly provided as the first type parameter.

type TokenData = { mint: Address; owner: Address };
type MintData = { supply: bigint };
const [myAccountA, myAccountB] = await fetchJsonParsedAccounts<[TokenData, MintData]>(rpc, [myAddressA, myAddressB]);
myAccountA satisfies MaybeAccount<TokenData> | MaybeEncodedAccount;
myAccountB satisfies MaybeAccount<MintData> | MaybeEncodedAccount;

decodeAccount()

This function transforms an EncodedAccount into an Account (or a MaybeEncodedAccount into a MaybeAccount) by decoding the account data using the provided Decoder instance.

type MyAccountData = { name: string; age: number };

const myAccount: EncodedAccount<'1234..5678'>;
const myDecoder: Decoder<MyAccountData> = getStructDecoder([
    ['name', getStringDecoder({ size: getU32Decoder() })],
    ['age', getU32Decoder()],
]);

const myDecodedAccount = decodeAccount(myAccount, myDecoder);
myDecodedAccount satisfies Account<MyAccountData, '1234..5678'>;

assertAccountDecoded()

This function asserts that an account stores decoded data, ie not a Uint8Array. Note that it does not check the shape of the data matches the decoded type, only that it is not a Uint8Array.

type MyAccountData = { name: string; age: number };

const myAccount: Account<MyAccountData | Uint8Array, '1234..5678'>;
assertAccountDecoded(myAccount);

// now the account data can be used as MyAccountData
account.data satisfies MyAccountData;

This is particularly useful for narrowing the result of fetching a JSON parsed account.

    const account: MaybeAccount<MockData | Uint8Array> = await fetchJsonParsedAccount<MockData>(
        rpc, 
        '1234..5678' as Address,
    )

    assertAccountDecoded(account);
    // now we have a MaybeAccount<MockData>
    account satisfies MaybeAccount<MockData>

assertAccountsDecoded

This function asserts that all input accounts store decoded data, ie not a Uint8Array. As with assertAccountDecoded it does not check the shape of the data matches the decoded type, only that it is not a Uint8Array.

type MyAccountData = { name: string; age: number };

const myAccounts: Account<MyAccountData | Uint8Array, Address>[];
assertAccountsDecoded(myAccounts);

// now the account data can be used as MyAccountData
for(const a of account) {
    account.data satisfies MyAccountData;
}